Microphonic signaling device.



J. GARDNER.

MICROPHONIC SIGNALING DEVICE.

APPLICATION FILED JULY 18. 1914.

1,225,429. Patented May8-,1917.

2 SHEETSSHEET I.

J. GARDNER.

MICROPHONIC SIGNALING DEVICE.

APPLICATION HLED JULY I8. 1914.

1,225,429. PatenTed May 8, 1917.

2 SHEETS-SHEET 2.

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JOHN GARDNER, OF KNOTT END, ENGLAND.

MICROPHONIC SIGNALING DEVICE.

Specification of Letters Patent.

Patented. May 8, 1917.

Application filed July 18, 1914. Serial No. 851,702.

To all whom it may concern:

Be it known that I, JOHN GARDNER, a

' subject of the King of Great Britain and Ireland, and a resident of Knott End, in the county of Lancaster, England, have invented certain new and useful Improvements in Microphonic Signaling Devices, of which the following is a specification.

In the specifications to my prior British Letters Patent Nos. 11021 of 1906 and 15298 of 1907 I have described the construction of signaling devices by means of which a be of the nature described in my said prior signal is given as the result of the vibrations cated vibrations. In carrying this invention into effect the reed is of substantially stouter and diiferent construction than the reed of a sound operated instrument, so as not to be operatively affected solely by sound vibrations. In a preferred form of construction two parallel reeds are disposed so as to form an approximately V-shaped gap between them open. at the. bottom with a piece of electricity conducting material placed loosely between them and supported between V the walls of'the gap. The course of the current is from one wall of the gap to the other through the interposed conducting or bridging piece. These parts form the microphone device and the microphonic circuit (and the signaling devices affected by and from the vibrations of the microphonemay patent specifications.

The physically communicated vibrations I tooperate the improved instrument and to give the signals may, for example, be those communicated to a railway sleeper or tie by the passage of a train over its rails, the instrument or its microphonic part being placed on such sleeper or otherwise so put in communication with it that such vibrations arephysically communicated to the microphone. The ultimate signaling instrument may be placed at any required distance from the microphone instrument.

The accompanying drawings illustrate the construction of an instrument which is particularly applicable for use on a railway, and also shows its connection with a suitable type of ultimate signaling instrument.

Figure 1 shows the vibratory microphonic instrument in vertical section.

Fig. 2 shows it in plan with the lid of its casing removed.

Fig. 3 is an end view of the reeds with the loose contact pieces between them.

Fig. 4 is a view of the microphonic instrument in circuit with an electric bell to give an alarm.

Fig. 5 is a View of an arrangement which includes a modified form of bell.

A and A are two parallel and substantially thick brass strips, bars, or reeds, each held at one end horizontally in a holder or support comprising two metal disks B B which are secured to the bottom of the metallic casing C and grip the reeds between them. The reeds A and A are electrically insulated fromone another and from their holder by mica or like insulating material which will freely transmit to the reeds any vibrations physically communicated to the casing and the reed holder. The reeds are so twisted or shaped that when viewed from their free ends as in Fig. 3 they resemble abroad letter V with the limbs inclined to one another at an angle of about 90 but separated at their lower edges. Placed on the upper and inner faces of the reeds and opposite to each other are two flat carbon electrodes D Dlwhich also produce an open bottom V-shaped gap between them. Between the two electrodes D and D and upon them is laid a light and freely movable cylindrical carbon rod E parallel to the reeds. This rod E forms a bridging piece between the electrodes D and D and is small enough to fall down nearly to the bottom of the gap between them, but is not small enough to pass through the opening between their lower edges. Its ends are enlarged so that it cannot longitudinally displace itself from between the two electrodes D and D when in use. The electrodes D D are only in communication witheach other, to close their electric circuit,-through the rod E. The wires of this circuit, whichincludes a suitable battery or other source of electricity, are connected to the reeds at F F. The path of the electric current is along one reed, through its attached electrode, through the rod E, through the electrode of the other reed, and through such other reed. When the reeds are effectively vibrated the current passing through the circuit is reduced in quantity from that passing when the reeds are quiescent and a signaling instrument is operated as a"result of such reduction of current.

The electrodes D D are preferably placed on reeds at points between nodes and antinodes.

In Fig. 4 the circuit a of the vibratory microphonic device is shown as including a relay, the tongue of which can open and close another circuit containing a battery and a bell.

The reeds A A and the rod E are in circuit with a battery G and the coils H of a relay. When all is quiet the amount of current passing through the reeds and the rod E is suflicient to energize the coils of the relay sufficiently to hold over the relay tongue J in the position shown in Fig. 4. When the reeds A A are vibrated the resistance in their circuit increases, and the amount of current passing through the coils [H is not suflicient to hold the tongue J over in the illustrated position. The tongue then moves to a contact K to close a circuit containing a battery L and an electric bell M. The bell then rings. When the vibrations of the reeds cease, the resistance in their circuit falls to the normal again, and suflicient current then flows through the coils H to pull the relay tongue J over to the illustrated position and open the bell circuit. The bell then ceases to ring.

, In the arrangement shown in Fig. 5 the reeds are shown as operating in conjunction with an instrument which is both a relay and a bell, and with which only one battery is necessary for both the reed circuit and the bell and relay circuit. This relay bell is not herein claimed per 86.

This bell instrument has two sets ofcoils, one set of which H acts as relay coils, and the other set of which N acts as bell ringing coils. The armature O mounted on the usual spring 0 extends across the poles of both sets of coils. When the reeds A A are quiescent the amount of current flowing through the coils H is sufiicient to hold the armature 0 up against all the coil poles as shown, and the trembler contacts P are open and the bell coils are cutout of circuit. When the reeds vibrate and the resistance of their circuit is increased, the pull of the coils H is not sufiicient to hold the armature 0 in the illustrated position, and the spring 0 brings the trembler contacts against each other and the bell rings in the usual manner as long as the vibrations of the reeds continue and the coils H are not sufficiently energized to hold the armature. When the reeds cease to vibrate the, current in their circuit is restored to suflicient strength to energize the coils H sufiiciently to hold the armature in the illustrated position with the trembler contacts open, and the bell coils consequently out of action. The bell then ceases to ring.

For use to give a signal upon the passage of a train on a railway the casing may be placed on a sleeper or tie of the track over which the train will pass. When it arrives at or near suchtie the train vibrates the tie sufficiently to ,physically communicate operative vibrations to the reeds which in turn then effect the ringing of the bell in the manner described. The bell may be placed at any distance away from the tie on which the vibratory instrument is placed.

Instead of being placed'on a tie the vibratory instrument may be otherwise placed adjacent to the track, but so as to be operated by. the vibrations of passing trains.

Any of the ordinary semaphore or other signaling devices used on a railway may operate to open or close any of the circuits of the signaling apparatus.

The reed circuit may contain an easily adjustable resistance or rheostat indicated at R to enable it to be easily set or adjusted so as to operate upon any predetermined amount or extent of vibration being physically communicated to the reeds. Thus the normal current may be so much in excess of that required to merely hold over the relay tongue or the like that very energetic vibra' tions of the reeds and consequent substantial reduction of current would be required to release such tongue.

' Other signaling instruments than bells may. be included in the circuit governed from the microphonic vibrator.

What I claim is 1. A microphonic instrument comprising two vibratory reeds each supported at one end and having a current conducting element at the other end, said reeds vibrating in a vertical plane, a current conducting member bridging said conducting elements, said member resting upon said elements and being maintained in position thereon by gravity.

2. A microphonic instrument comprising two vibratory reeds each supported at one end and carrying an electrode at the other, said reeds vibrating in a vertical plane, said electrode comprising pieces arranged to provide a V-shaped space between them, a cylindrical electrode bridging said first named electrodes and positioned in said V-shaped space, said cylindrical electrode being maintained: in contact with said first named electrodes by gravity. 7

3. A microphonic instrument comprising a support, two vibratory reeds comprising flat strips each secured at one end of said support, said reeds vibrating in a vertical plane and having theirfree ends provided with electrodes arranged to form a V-shaped space between them, a cylindrical electrode 10 bridging said first named electrodes and positioned in said V-shaped space, said cylindrical electrode being maintained in contact with said first named electrodes by gravity.

In Witness whereof I have hereunto set' 15 my hand.

JOHN GARDNER. 

